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2019年06月21日 03:27:43

哈尔滨引产A deserted German satellite was close to crashing into Beijing before it eventually plunged into the Indian Ocean last October, Daily Telegraph reported.据英国《每日电讯报》报道,去年10月,一枚废弃的德国卫星在坠入印度洋之前,曾差点坠落北京。The European Space Agency told Das Spiegel magazine that its new calculations have discovered that if the 2.5-ton Rosat satellite#39;s re-entry had been delayed for seven more minutes, the Chinese capital of 20 million people would have faced a deep impact.欧洲宇航局向德国《明镜》杂志透露,最新测算结果表明,如果这枚2.5吨重的;伦琴;号卫星重返地球的时间再推迟7分钟,拥有2000万人口的中国首都北京将面临;深度撞击;。The satellite#39;s remnants, travelling at speeds of 280mph (450.6kph), would have destroyed buildings, left craters and almost certainly caused causalities.卫星的残余部分坠落时速达到280英里(450.6公里),将会摧毁建筑、形成撞击坑,一定会造成人员伤亡。 /201202/169932哈市市立医院好不好?After 500,000 miles of road tests, Google#39;s self-driving car team gave New Yorker writer Burkhard Bilger unusually deep access for a profile this week.经过50万英里的道路测试之后,谷歌(Google)的自动驾驶汽车团队本周不同寻常地让纽约作家比尔格(Burkhard Bilger)深度了解了这款汽车的情况。It#39;s still unclear whether the larger idea of autonomous cars will work at all - the most optimistic estimate seems to be that they will come to market in five to 10 years.现在还不清楚自动汽车这一宏大概念能否行得通――最乐观的估计似乎是,它们将在5到10年内进入市场。But self-driving cars are what put Google on the map as a company that tries to make science fiction into reality, so the tale of how they came to be is compelling.但自动驾驶汽车让谷歌成为出了名的试图将科幻变成现实的公司,因此关于其概念如何形成的故事也引人注目。The hero of Bilger#39;s story is 33-year-old engineer Anthony Levandowski, who joined Google after building a self-driving motorcycle for the DARPA Grand Challenge (though it sounds like that didn#39;t work all that well). Levandowski was toiling away on Google Street View with the more-famous inventor/professor Sebastian Thrun before the two of them got the go-ahead from Google co-founders Larry Page and Sergey Brin to start working on self-driving cars.比尔格报道的主角是33岁的工程师莱万多斯基(Anthony Levandowski),他加入谷歌之前为美国无人驾驶汽车挑战赛(DARPA Grand Challenge)设计了一款自动驾驶托车(不过听上去这款车运行起来不怎么样)。莱万多斯基在谷歌与更有名的发明家兼教授特龙(Sebastian Thrun)一起埋头开发谷歌街景(Google Street View),后来他们二人得到谷歌联合创始人佩里(Larry Page)和布林(Sergey Brin)的许可,开始致力于自动驾驶汽车专案。What made the difference? A TV show producer#39;s wacky idea for a stunt, believe it or not.对无人驾驶汽车这个概念产生重大影响的是什么?信不信由你,这个项目始于一个电视节目制作人想出来的雷人噱头。From Bilger#39;s piece:比尔格的报道中说:#39;In February of 2008, Levandowski got a call from a producer of #39;Prototype This!,#39; a series on the Discovery Channel. Would he be interested in building a self-driving pizza delivery car? Within five weeks, he and a team of fellow Berkeley graduates and other engineers had retrofitted a Prius for the purpose. They patched together a guidance system and persuaded the California Highway Patrol to let the car cross the Bay Bridge-from San Francisco to Treasure Island. It would be the first time an unmanned car had driven legally on American streets.#39;2008年2月,莱万多斯基接到探索频道(Discovery Channel)系列节目“Prototype This!”一位制作人的电话,问他有没有兴趣打造一款自动驾驶的披萨配送车?在五个星期内,他和一个由伯克利校友以及其他工程师组成的团队就改造了一辆普瑞斯(Prius)。他们拼凑出一个导航系统,并说加州高速公路巡警(California Highway Patrol)让这辆车驶过海湾大桥――从旧金山行驶到金银岛。这是无人驾驶汽车首次合法地在美国街道上行驶。The successful bridge crossing earned Page and Brin#39;s go-ahead within a few months, according to Thrun.特龙说,这次成功的“过桥行使”让他们获得了佩奇和布林的首肯,在接下来几个月的时间里继续从事这项研究。Then the two Google co-founders, #39;like boys plotting a scavenger hunt,#39; gave the self-driving car team a set of 10 100-mile itineraries. #39;The roads wound through every part of the Bay Area- from the leafy lanes of Menlo Park to the switchbacks of Lombard Street. If the driver took the wheel or tapped the brakes even once, the trip was disqualified.#39; The team completed all 10 in a year and a half.接下来,谷歌的两位共同创始人像计划着进行“寻物游戏”的孩子一样,给自动驾驶汽车团队设定了10条100英里的路线。这些路线经过了湾区的每一个部分,从门洛帕克(Menlo Park)的林荫道到隆巴德街(Lombard Street)之字爬坡路线。如果驾驶者动了方向盘或是踩了刹车,这次行程就算没通过。在一年半的时间里,团队完成全部10条路线。There#39;s a lot more to the story, but the real question is, what#39;s next for the self-driving car? There are challenges on multiple fronts, now that the scavenger-hunt phase is over. 1) Jumping over legal hurdles. 2) Figuring out how to bring the cars to market, given carmakers are allergic to the word #39;self driving#39; (though they#39;re OK with smaller and subtler tweaks, where machine smarts help drivers out). And 3) Making next technological leaps forward in sensors and machine learning. Even if autonomous cars are statistically safer, any mistake will tarnish the entire endeavor.关于这个故事,还有很多东西可讲,但真正的问题在于,自动驾驶汽车的下一步往哪里走?“寻物游戏”这一阶段走过之后,这个项目在很多方面都面临着挑战。1)越过法律上的障碍;2)在市场已经对“自动驾驶”一词过敏的情况下,找出把汽车推向市场的方法(不过把这这个词稍微改动一下,表明机器智能能为驾驶者提供帮助,市场就会接受);3)在传感器和机器学习方面再一次实现技术飞跃。即便有统计数据表明自动驾驶汽车更安全,但如果出现任何错误还是会让全部努力受到损害。As Bilger reports, #39;The car has trouble in the rain, for instance, when its lasers bounce off shiny surfaces. (The first drops call forth a small icon of a cloud onscreen and a voice warning that auto-drive will soon disengage.) It can#39;t tell wet concrete from dry or fresh asphalt from firm. It can#39;t hear a traffic cop#39;s whistle or follow hand signals.#39;比尔格在报道里写道,比如,这种车在下雨的时候会遇到麻烦,因为这时候激光会在光滑的表面反射。(最初的几滴雨水会让屏幕上出现一个云朵状的小图标,然后就有声音提醒自动驾驶功能即将关闭。)这种车无法区分湿混凝土和干混凝土,刚铺好的沥青和已经坚实的沥青。它听不见交警的哨音,也无法遵从交通手势的指引。At the same time, the car is often smarter than a human. For instance, it can prepare to brake preemptively based on traffic data about a slowdown coming ahead, or slow to a crawl at nighttime on a wooded road when it senses a deer walking on the shoulder.与此同时,汽车通常比人更聪明。比如,汽车可以通过交通数据发现前方需要减速,因此做好制动减速的准备,或是在夜间林地行车发现路肩上有一头行走的鹿的时候减速慢行。And improvements are coming, says Bilger: #39;At the tech meeting I attended, Levandowski showed the team a of Google#39;s newest laser, slated to be installed within the year. It had more than twice the range of previous models - eleven hundred feet instead of two hundred and sixty - and thirty times the resolution. At three hundred feet, it could spot a metal plate less than two inches thick. The laser would be about the size of a coffee mug, he told me, and cost around ten thousand dollars-seventy thousand less than the current model.#39;比尔格说,会不断地有所改进。他说,在我参加的这次科技会议上,莱万多斯基向团队展示了一个谷歌最新激光装置的视频,按计划该激光装置将在今年内装备到汽车上;新装置的探测范围是以前型号的两倍――从260英尺增加到1,100英尺,分辨率是以前型号的30倍。在300英尺远的地方,该装置可以发现厚度小于两英寸的金属牌;他告诉我,这一激光装置的尺寸只有一只咖啡杯大小,价格为1万美元,比当前的型号要低大约7万美元。 /201311/265470哈尔滨妇科医院哪个最好


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